The invention relates to a device for producing a gas-and-liquid mixture, such as for intake by humans, comprising a supply member for the liquid and a feeding arrangement for the gas. In certain cases of a liquid being taken in by humans there is an advantage of a certain amount of gas being admixed to the quantity of liquid taken.
It is thus known from Double Contrast Gastrointestinal Radiology, by Igor Laufer, M.D., published in Philadelphia, U.S.A., and especially from Chapter 4, page 79, therein, that for the purpose of an X-ray examination of the upper digestive tract of humans, the patient must first take an effervescent agent, and thereupon a quantity of contrast liquid. The coming together of the effervescent agent and the contrast liquid then results in the formation of a gas-and-liquid mixture which causes a double-contrast effect to appear, thus rendering more details better visible in the roentgenograms or, in case of direct observation, on luminous screens, than would be the case if use were made of a contrast medium only. This method entails a number of drawbacks. For example, an effervescent agent must be taken first, followed very rapidly thereafter by the intake of the contrast medium, it thereupon being necessary to administer yet another agent for preventing bubbles of an undesirable size from forming in the gas-and-liquid mixture. The desired gas-and-liquid mixture furthermore only has a limited useful life, since the gas vanishes from the mixture, without any possibility of new gas being formed after the effervescent agent has been used up. There is, moreover, no convenient method of restoring the desired gas-to-liquid ratio in the mixture by means of a repeated intake of a quantity of effervescent agent. Nonactivated effervescing particles can give rise to an erroneous interpretation of the X-ray picture obtained.
Further drawbacks consist in the difficulty of apportioning the established dose of liquid, and in the trial-and-error method of establishing the proper quantities of the aforementioned components for attaining an optimum double-contrast effect. Besides, this method is often difficult to use for certain patients, including a number of elderly persons, and not at all for young children. The invention aims at providing a device allowing an even more effective gas-and-liquid mixture to form in a simpler manner upon the intake of the liquid, without any effervescing or other agents being required. This aim is attained according to the invention by providing the device with a supporting surface for the upper lip and a supporting surface for the lower lip, in such a way that gas and liquid and being simultaneously supplied during the intake. Advantages of the device according to the invention are that effervescing or other agents are no longer needed, that the mixture produced has a relatively long useful life, and that the mixture can be replenished at any time. The use of the device also allows such groups as elderly persons and young children to be examined, since the intake fundamentally leaves intact the normal course of the drinking process.
The absence of the need for taking any other agents also obviates the possible presence of such artifacts as undissolved particles which might stand in the way of a correct interpretation of the data obtained. It is a very special advantage that the entire esophagus can now be viewed in double contrast.
Finally, it should be observed that, with the use of the device according to the invention, no overpressure is required, unlike the practice of the siphon method which is occasionally used and by which a gas-and-liquid mixture under excess pressure is forced through a swallowed tube directly into the esophagus (Double Contrast Gastrointestinal Radiology, by Igor Laufer, M.D., Chapter 4, page 80). Such a use of overpressure interferes with the normal ingestive process, which can sometimes be unacceptable, such as in the case of elderly persons and young children. Moreover, there is a risk of the esophagus being perforated.